Databases
StackOverflow2013
Postsdbo
POWhy is Hibernate selecting same columns 4 times? Help with Mapping?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWhy is Hibernate selecting same columns 4 times? Help with Mapping?
    primarykey
    data
    text
    <p>My classes look like these. Why does the same column get selected 4 times? What is problem with the mapping?</p> <pre><code>@Entity @Table(name="CLIENTS") public class Client implements Serializable { @Id @GeneratedValue @Column(name="GENERATED_ID") private Long id; @Column(name="NAME") private String name; @OneToMany(cascade=CascadeType.ALL, mappedBy="client", fetch=FetchType.EAGER) private Map&lt;ParamPK, Param&gt; params = new HashMap&lt;ParamPK, Param&gt;(); } @Entity @Table(name="PARAMS") public class Param implements Serializable { @EmbeddedId private ParamPK paramPK; @Column(name="VALUE") private String value; @ManyToOne @MapsId("clientId") private Client client; } @Embeddable public class ParamPK implements Serializable { @Column(name="PARAM_KEY") private String key; @Column(name="CLIENT_GENERATED_ID") private Long clientId; } </code></pre> <p>The queries generated by select gets same column 4 times.</p> <pre><code>/* from Client */ select client0_.GENERATED_ID as GENERATED1_1_, client0_.NAME as NAME1_ from CLIENTS client0_ /* load one-to-many Client.params */ select params0_.client_GENERATED_ID as client3_1_1_, params0_.client_GENERATED_ID as client3_1_, params0_.PARAM_KEY as PARAM1_1_, params0_.CLIENT_GENERATED_ID as CLIENT3_1_, params0_.client_GENERATED_ID as client3_0_0_, params0_.PARAM_KEY as PARAM1_0_0_, params0_.VALUE as VALUE0_0_ from PARAMS params0_ where params0_.client_GENERATED_ID=? </code></pre> <p>Note using Hibernate 3.5.3. Rest boilerplate code has been removed as irrelevant.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USRam
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POWhy is Hibernate selecting same columns 4 times? Help with Mapping?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POWhy is Hibernate selecting same columns 4 times? Help with Mapping?
      1. This table or related slice is empty.
      1. VTUpMod
    1. COCould you show the JPQL query?
      singulars
      1. POWhy is Hibernate selecting same columns 4 times? Help with Mapping?
      1. USJasper
    2. CONot sure it will help, but have you tried adding a MapKey(name = "paramPK") annotation on your Map<ParamPK, Param>?
      singulars
      1. POWhy is Hibernate selecting same columns 4 times? Help with Mapping?
      1. USJB Nizet
    3. CO@Psy the query is plain `em.createQuery("from Client");`
      singulars
      1. POWhy is Hibernate selecting same columns 4 times? Help with Mapping?
      1. USRam
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload